Synthetic filaments having antistatic properties comprising a continuous nonconducting sheath of synthetic polymer surrounding a conductive polymeric core containing carbon black have been taught by Hull in U.S. Pat. No. 3,803,453. The cross-section of the core shown in said patent is circular. Need has arisen in certain end-use applications, such as career apparel worn in clean rooms, for even greater reduction of static propensity, and contrary to the desires expressed by others to conceal the fiber blackness, is a desire for greater visibility of the core.
Sheath-core filaments wherein the cross-section of the core is trilobal are known. They can be prepared with a spinneret of the type shown in U.S. Pat. No. 2,936,482. While useful products of the invention can be prepared with such spinnerets, improvements in preserving definition of the trilobal core through the spinning process is a worthwhile objective. The present invention offers an improved spinning technique as well as providing a novel filament which rapidly dissipates electrical charges.